Positive negative voltage power adapter

The utility model discloses a positive negative voltage power adapter, including electric capacity C1, chip IC1, triode V1 and second grade D5, input voltage U1, diode D6's positive pole, chip IC1's pin 1, chip IC1's pin 4 are connected to electric capacity C1's one end, and pin 10 and ground connection that electric capacity C3, electric capacity C10, electric capacity C11, resistance R1, transient voltage restrain diode D8, chip IC1's pin 9 and chip IC1 are connected to electric capacity C1's the other end. The utility model discloses complicated transformer structure has been abandoned to the positive negative voltage power adapter circuit, adopts the K174YH7 chip to form the output function that positive negative voltage was realized to the square wave form oscillator, and simple structure, components and parts are few simultaneously, consequently has integrated level height, output is stable, interference immunity is strong advantage.